The molecules of air surged through the beast’s throat down a slippery tube and into the buoyancy bladder. Inside the membrane, blood vessels seine out the oxygen, maintaining a strategy that started perhaps 150 million years ago when this fish’s ancestors may have reptiled about the banks of a long ago sea. The mighty tail thrusts and propels it across the surface of the Rio Grande to lurk under a thicket of Giant Cane.
The largest Alligator Gar ever caught on a rod and reel came from the Texas side of the Rio Grande in 1951. At over seven feet long and 279 pounds, this marine leviathan ranks with the largest freshwater fish in the world.
The Alligator Gar has two rows of upper teeth and a powerful jaw both very much like the saltwater crocodile. A carnivore with a reptile-like ball and socket vertebrae and the ability not only take oxygen from the water with its gills but also to breathe out of water with a lung, this fish and its history have confounded scientists for years. Is it a fish trying to become a reptile, or a reptile that morphed into fishness?
Unusually well preserved fish fossils of the Green River, take the gar back over 100 million years ago, but new DNA research suggests this creature may have come from the Jurassic period or 150 MA. Either dating, the evidence suggests the fish has changed very little over the eons.
The diamond shaped interlocking scales that were once used by Native Americans for jewelry, breast plates and arrow tips, cover the fish in a tight armor and are part of the hydro-dynamics that make this fish a swift and great hunter.
The life span of an Alligator Gar runs 50-75 years but an increased mortality rate caused by pollution, dwindling habitat, and un-regulated fishing, is threatening the gar’s future. No longer found in the Upper Ohio Valley, many states have imposed bag limits. Texas and Louisiana still allow unlimited gar fishing, but in March, Texas Parks and Wildlife will host a public meeting to consider limiting commercial and sport fishers to one gar per day.